Kapil Arya

Microwave Assisted Synthesis of Fluorinated Hexahydro 1,3,5‐Triazine Derivatives in Aqueous Medium and One Pot Synthesis of 1,2,4‐Triazolo(4,3‐a)1,3,5‐triazines

Abstract A multi‐component condensation of substituted phenylthiourea/urea, aqueous formaldehyde and substituted aromatic/heterocyclic amines lead to 2‐thioxohexahydro‐1,3,5‐triazines (4) in aqueous medium under microwave irradiation in 30–60 sec in quantitative yield with reasonable purity. Further, triazolo[4,3‐a]triazines were also prepared by a one‐pot reaction of ‘in situ’ synthesized triazinyl hydrazine (7) with CS2 (9).

MICROWAVE INDUCED DRY-MEDIA SYNTHESIS OF SPIRO[INDOLE-THIAZOLIDINONES/ THIAZINONES] AS POTENTIAL ANTIFUNGAL AND ANTITUBERCULAR AGENTS AND STUDY OF THEIR REACTIONS

A series of new spiro[3H-indole-3,2′-thiazolidine]-2,4′(1H)-diones (IV) and spiro[3H-indole-3,2′-tetrahydro-1,3-thiazine]-2,4′(1H)-diones (V) have been synthesized in 85–93% yield by the one-pot environmentally benign microwave induced technique involving the cyclocondensation of 3-arylimino-2H-indol-2-ones (III) with thioacids viz. mercapto aceticacid (a)/3-mercapto propionicacid (b) using montmorillonite KSF as inorganic solid support. Intermediates (III) were synthesized in situ by the reaction of indole-2,3-diones (I) and substituted anilines (II). The spiro compounds have been further subjected to solvent-free acetylation, aminoalkylation and thiation under microwave irradiation using solid supports. The synthesized compounds have been screened in vitro for antifungal activity against Rhizoctonia solani, Fusarium oxysporum, and Collectotrichum capsici, and antitubercular acivity against Mycobacterium tuberculosis.

Microwave assisted one pot synthesis of a series of trifluoromethyl substituted spiro [indole–triazoles]

Abstract A series of trifluoromethyl substituted spiro [3H-indole-3,3′-[3H-1,2,4]triazoles]-2(1H)-ones have been synthesized in 85–90% yield by one pot environmentally benign microwave induced techniques involving the condensation of 3-arylimino-2H-indol-2-ones (III) with thiosemicarbazide (IV) using montmorillonite as solid support. This 3-arylimino-2H-indol-2-ones (III) was synthesized in situ by the reaction of fluorinated indole-2,3-diones (I) and fluorinated anilines (II). The advantages obtained by the use of microwave irradiation were demonstrated.

Green chemical approach for facile one-pot synthesis of 2,4,8-trisubstituted-1,5-benzothiazepines and their dioxides under microwave irradiation

2,4,8-Trisubstituted-1,5-benzothiazepines (synthesized ‘in situ’) have been selectively oxidised to the corresponding sulfones via a one-pot procedure in 9 min. with 91% yield under microwave irradiation coupled with clay-supported ferric nitrate.

Multistep microwave assisted solvent free green chemical synthesis of 2,7-dihydro-3H-pyridazino[3',4':4,5]indolo[3,2-c]quinoline-3,13(12H)-dione

A novel class of biologically active compound 2,7-dihydro-3H-pyridazino[3′,4′:4,5]indolo[3,2-c]quinoline-3,13(12H)-dione (10a–b)has been achieved efficiently and quickly under solvent free conditions in an open vessel microwave system. The multi step one pot synthesis involved the reaction of 8,9,10,11-tetrahydro-6H-indolo[3,2-c]quinoline-6,7(5H)-dione (6a–d) and glyoxylic acid monohydrate followed by cyclocondensation with hydrazine hydrate under microwave irradiation. The synthesis of 8,9,10,11-tetrahydro-6H-indolo[3,2-c]quinoline-6,7(5H)-dione(6a–d) has also been described from the reaction of (2-oxo-1,2-dihydroquinolin-4-yl)hydrazine with 1,3-cyclohexanedione in the absence of any solvent/catalyst/strong acid or solid support using microwaves.

Facile One Pot Microwave Induced Synthesis of Spiro [Indole-pyrazoles] and Spiro [indol-isoxazoles]

The potential of domestic microwave oven has been utilized in an elegant one step synthesis of a series of new fluorine containing spiro [indole-pyrazoles] and spiro [indol-isoxazoles] in 85-95% yields. Results were compared with those obtained following the classical method which involves synthesis in three steps. The advantages obtained by the use of microwave irradiation were demonstrated.